Single beam bridge crane is a kind of lifting equipment which is used to lift materials horizontally over workshop, warehouse and stock yard. Because its two ends are located on tall concrete columns or metal brackets, the shape is like a bridge. The bridge of single beam bridge crane runs longitudinally along the track laid on the viaduct on both sides, which can make full use of the space under the bridge to lift materials without being hindered by the ground equipment. It is the most widely used and the largest number of lifting machinery.
https://www.dowell-cranes.com/overhead-crane/5-ton-bridge-crane.html